text: In chemistry, acylation is a broad class of chemical reactions in which an acyl group () is added to a substrate. The compound providing the acyl group is called the acylating agent.  The substrate to be acylated and the product include the following:
  *alcohols, esters
  *amines, amides
  *arenes, ketones
  A particularly common type of acylation is acetylation, the addition of the acetyl group. Closely related to acylation is formylation, which employ sources of "HCO in place of "RCO".